Dynamic Bandwidth Allocation Algorithm Research Articles

Dynamic bandwidth allocation algorithms for improved throughput and latency performance in CDMA-based next-generation ethernet passive optical networks

In this paper, we propose new scheduling algorithms to improve the performance of the code division multiple access (CDMA) enabled next generation ethernet passive optical networks (NG-EPON). The original dynamic bandwidth allocation (DBA) scheme based on a round robin scheduling algorithm was originally proposed for the first generation CDMA based EPON where the network throughput and delay requirements per optical network unit (ONU) are relatively moderate. On the other hand, in the NG-EPON standard, the network capacity is increased up to 100 Gb/s and stringent requirements are applied to the packet delay. For this reason, in this work, we propose new scheduling algorithms for NG-EPON to assign a grant size on each upstream CDMA code in order to guarantee the newly required network throughput and delay performance. The first DBA algorithm is the first in first out (FIFO) algorithm in which the ONU requests are ordered in terms of their request arrival time. The second scheme is the reservation pattern (RP) algorithm in which each ONU starts transmitting its queue content in its reserved pattern of subcycles following a pre-defined pattern. The performances of the newly proposed algorithms are evaluated and compared. Results show that both newly proposed scheduling schemes can significantly improve the network performance in terms of the packet delay, jitter, and throughput. In addition, the results are compared to many dynamic wavelength and bandwidth allocation (DWBA) algorithms. The results show that the performances are comparable and that CDMA can be a good alternative for WDM for multi-channels based NG-EPON.

Impact of security breach on the upstream delay performance of next generation gigabit passive optical networks

The next generation passive optical networks (NG-GPON) such as long reach GPON is the future-proof solution to answer the continuous demands for access user bandwidth and network expansion. However, security which is yet to be addressed in NG-GPON needs urgent attention as it will become more critical due to much longer distance, denser user population and more network elements. In addition, the longer propagation delay in NG-GPON can also lead to a more complex bandwidth allocation mechanism that is expected to operate in a dynamic manner. Among the highlights of recommendations for future implementation are improvements in the security aspect and the use of dynamic bandwidth allocation (DBA) algorithm that suit the characteristics of long reach GPON. Current PON is exposed to degradation attack, a security breach that can harm how bandwidth fairness mechanism among ONUs work. Thus, this project proposes a secured DBA mechanism for NG-PON that could overcome this particular threat. In specific, a detection phase will be included in the DBA mechanism to sense and subsequently mitigate abnormal behaviours among ONUs that are harmful to the goal of DBA i.e. to ensure QoS among ONUs and traffics. At the same time, careful attention is given on the delay parameter as it is a critical parameter that can affect DBA performance in long reach GPON. In this paper, preliminary analysis is shown that reveal how possibility of threats increase with increasing of distance and network elements.

Efficiency Tests of DBA Algorithms in XG-PON

Sophisticated dynamic bandwidth allocation (DBA) algorithms can dramatically improve or worsen throughput and delay in whole networks. It is very important to choose the right DBA algorithm. Our work tests static assignment and three DBA algorithms, namely GigaPON Access Network DBA, Hybrid Reporting Allocation, and modified Max–Min Fair. All tests were made on our simulator of ten-gigabit passive optical network DBA specially developed for testing DBA algorithms. The tests verify delay of each optical network unit and amount of waste with bandwidth. This paper describes how the used DBA algorithms work and the processes involved in DBA algorithms.

Machine Learning-Based Bandwidth Prediction for Low-Latency H2M Applications

Human-to-machine (H2M) communications in emerging tactile-haptic applications are characterized by stringent low-latency transmission. To achieve low-latency transmissions over existing optical and wireless access networks, this paper proposes a machine learning-based predictive dynamic bandwidth allocation (DBA) algorithm, termed MLP-DBA, to address the uplink bandwidth contention and latency bottleneck of such networks. The proposed algorithm utilizes an artificial neural network (ANN) at the central office (CO) to predict H2M packet bursts arriving at each optical network unit wireless access point (ONU-AP), thereby enabling the uplink bandwidth demand of each ONU-AP to be estimated. As such, arriving packet bursts at the ONU-APs can be allocated bandwidth for tranmission by the CO without having to wait to transmit in the following transmission cycles. Extensive simulations show that the ANN-based prediction of H2M packet bursts achieves >90% accuracy, significantly improving bandwidth demand estimation over existing prediction algorithms. MLP-DBA also makes adaptive bandwidth allocation decisions by classifying each ONU-AP according to its estimated bandwidth, with results showing reduced uplink latency and packet drop ratio as compared to conventional predictive DBA algorithms.

Towards Immersive Tactile Internet Experiences: Low-Latency FiWi Enhanced Mobile Networks With Edge Intelligence [Invited

Historically, research efforts in optical networks have focused on the goal of continuously increasing capacity rather than on lowering end-to-end latency. This slowly started to change in the access environment with post-Next-Generation Passive Optical Network 2 research. The emphasis on latency grew in importance with the introduction of 5G ultra-reliable and low-latency communication requirements. In this paper, we focus on the emerging Tactile Internet as one of the most interesting 5G low-latency applications enabling novel immersive experiences. After describing the Tactile Internet's human-in-the-loop-centric design principles and haptic communications models, we elaborate on the development of decentralized cooperative dynamic bandwidth allocation algorithms for end-to-end resource coordination in fiber-wireless (FiWi) access networks. We then use machine learning in the context of FiWi enhanced heterogeneous networks to decouple haptic feedback from the impact of extensive propagation delays. This enables humans to perceive remote task environments in time at a 1-ms granularity.

Dynamic bandwidth allocation algorithm with demand forecasting mechanism for bandwidth allocations in 10-gigabit-capable passive optical network

10G-passive optical network (XG-PON) provides an emerging potential technology to carry multiple services for the first - mile access network. However, it offers 0.3 ms propagation delay between the optical network Unit (ONU) and optical line terminal (OLT) resulting in inevitable increased queuing delay for the bandwidth grants to the ONUs. We present a reasonable and effective uplink dynamic bandwidth allocation method - demand forecasting DBA (DF-DBA) that predicts ONU’s future demands by statistical modelling of the demand patterns and tends to fulfil the predicted demands just in time, which results in reduced delay. Results show that use of simple normal distribution in the DBA engine offers more appropriate bandwidth allocation with 14% decreased packet drop ratio (PDR) values than standard GigaPON access network (GIANT) DBA following request-grant cycle procedure. Proposed DBA when tested for all the T-CONTs, reduced 50% delay and offered 45% throughput improvement at higher traffic load. The unassigned bandwidth margin (UBM) is nearly ideal along with better QoS parameters results which validates that DF-DBA can practically improve the OLT performance. Further, this predictive DBA opens up a new horizon of research for researcher to use it for longer distances in PON (LR-PON) network with different statistical distributions for getting the possible best results in the future.

Dynamic hybrid slot-size bandwidth allocation algorithm for reducing packet delay and jitter variation of real time traffic in EPON

In the modern data networks, the demand is increasing for interruption free, high speed, and best quality of services to perform successful communications. This paper emphasizes on the high priority (HP) traffic like video conferencing, video streaming, telemedicine, teleconferencing, and interactive gaming for the real time communications. To achieve the best quality data communication for the HP traffic, in this paper, we propose a new dynamic bandwidth allocation (DBA) algorithm called dynamic hybrid slot-size bandwidth allocation (DHSSBA) algorithm, which is the modified version of existing hybrid slot-size/rate (HSSR) algorithm. The performance of the proposed scheme has been analyzed by using numerical simulations in terms of the end-to-end packet delay, absolute delay variation, jitter, and throughput for both the HP and best effort (BE) traffic. We have also compared the simulation results of the proposed scheme with those of the existing modified HSSR (MHSSR), delay variation guaranteed protocol (DVGP), and HSSR schemes. From the comparison of the simulation results, at the highest offered load of 1.0, it can be seen that for the HP traffic the proposed scheme provides 60%, 50%, and 20% less average end-to-end delay than the existing HSSR, DVGP, and MHSSR schemes, respectively. At the highest offered load of 1.0, the proposed scheme also provides about 35% higher throughput than both the HSSR and DVGP schemes with 45% and 35% less jitter variation than the HSSR and DVGP schemes, respectively.

QoS-Based DWBA Algorithm for NG-EPON

The next-generation Ethernet passive optical network (NG-EPON) is basically classified into two architectures on the basis of the wavelength sharing by the optical network units (ONUs). The single scheduling domain (SSD) and multi-scheduling domain (MSD) EPON are the two different design architectures for NG-EPON. A vital task in NG-EPON is to design dynamic wavelength bandwidth allocation (DWBA) algorithms that can meet the future demands of the network subscribers. A number of DWBA algorithms have been designed for time and wavelength division multiplex (TWDM) EPON. The existing DWBA algorithms for TWDM-EPON could be used in MSD-EPON by making necessary parametric changes. The design and implementation of new DWBA algorithms for MSD-EPON are still required specifically. In this paper, we have proposed a quality of service (QoS)-based DWBA algorithm for NG-EPON. We have comparatively analyzed our proposed DWBA with the existing algorithms like earlier finished time (EFT), weighted bipartite matching (WBM), and earlier finished time with void filling (EFT-VF). The results show that our proposed DWBA algorithm performs better as compared to EFT, WBM, and EFT-VF on the basis of average packet delay and average completion time for NG-EPON.

Demand Forecasting DBA Algorithm for Reducing Packet Delay with Efficient Bandwidth Allocation in XG-PON

In a typical 10G-Passive Optical Network (XG-PON), the propagation delay between the Optical Network Unit (ONU) and Optical Line Terminal (OLT) is about 0.3 ms. With a frame size of 125 μs, this amounts to three frames of data in the upstream and three frames of data in the downstream. Assuming no processing delays, the grants for any bandwidth requests reach the ONU after six frames in this request-grant cycle. Often, during this six-frame delay, the queue situation is changed drastically, as much, more data would arrive in the queue. As a result, the queued data that is delayed loses its significance due to its real-time nature. Unfortunately, almost all dynamic bandwidth allocation (DBA) algorithms follow this request-grant cycle and hence lacking in their performance. This paper introduces a novel approach for bandwidth allocation, called Demand Forecasting DBA (DF-DBA), which predicts ONU’s future demands by statistical modelling of the demand patterns and tends to fulfil the predicted demands just in time, which results in reduced delay. Simulation results indicate that the proposed technique out-performs previous DBAs, such as GigaPON access network (GIANT) and round robin (RR) employing the request-grant cycle in terms of Throughput and Packet delivery ratio (PDR). Circular buffers are introduced in statistical predictions, which produce the least delay for this novel DF-DBA. This paper, hence, opens up a new horizon of research in which researchers may come up with better statistical models to brew better and better results for Passive optical networks.

High-priority first dynamic wavelength and bandwidth allocation algorithm in TWDM-PON

Abstract Time and wavelength division multiplexing passive optical network (TWDM-PON) is the mainstream scheme of the next generation access network, and it possesses a number of unique characteristics such as high-bandwidth, long-distance data transmission, and connecting lots of users. As the difference among user traffic demands increases, in order to effectively decrease the network delay and improve resource utilization, a high-priority first dynamic wavelength and bandwidth allocation (HF-DWBA) algorithm in TWDM-PON system is proposed in this study. According to the service-level agreement (SLA), in order to determine the priority of an optical network unit (ONU), the proposed algorithm ensures the high-level ONU traffic distribution in terms of wavelength assignment and bandwidth allocation, and it can execute five types of transmission containers (T-CONTs) as well as four kinds of bandwidth allocation strategies. The results of simulation show that in comparison with traditional algorithms, the proposed HF-DWBA algorithm can effectively reduce end-to-end time delay and improve bandwidth utilization ratio, while making fairness among different types of bandwidth allocation strategies.

(Overlap and non-overlap)-based DBA algorithm with wavelength optimal length for upstream channel in multi-OLT PON

Abstract In this paper, an (overlap and non-overlap)-based dynamic bandwidth allocation (DBA) algorithm with wavelength optimal length (WOL) for upstream channel in multi-OLT passive optical network (PON) is proposed. By introducing optical line terminal (OLT) pool, the problem of OLT services imbalance is solved. Based on the service and its weight factor, proportion algorithm is constructed to allocate OLTs and wavelengths to OLT pool and wavelength group respectively. By proposing a new concept of WOL, the bandwidth wastage is reduced. By presenting overlap and non-overlap algorithms, the bandwidth utilization is improved further. By the simulation and analysis, the effectiveness of the proposed algorithms is demonstrated.

TWDM-PON中支持区分服务的节能动态波长带宽分配算法

TWDM-PON中支持区分服务的节能动态波长带宽分配算法

Adaptive dynamic wavelength and bandwidth allocation algorithm based on error-back-propagation neural network prediction

With the emergence of new services such as high-definition video, cloud computing and virtual reality, Wavelength Division Multiplexing/Time Division Multiplexing-Passive Optical Network (WDM/TDM-PON) has become a key technology for future access network. The development of Software Defined Networking (SDN) and machine learning also brings new opportunities to the flexibility of WDM/TDM-PON. In this paper, an Adaptive Dynamic Bandwidth Allocation algorithm based on error-back-propagation Neural Network Prediction (ADBA-NNP) was proposed to reduce the Round-trip-time (RTT) delay in the bandwidth-scheduling period. A Dynamic Wavelength Allocation (DWA) algorithm and a novel architecture of WDM/TDM-PON was proposed to simple the multi-carrier source. The experimental results validated that the proposed algorithm could dynamically allocate wavelengths under multi-carrier at 12.5G intervals. Compared with the traditional algorithms, the proposed algorithm could reduce the transmission delay by 25%.

Bandwidth Allocation and Control Message Scheduling Algorithms for Improving the QoSs of High Priority Traffic in PON

The passive optical network (PON) is the most promising candidate for supporting multiple service classes, i.e., high priority (HP) traffic and best-effort (BE) traffic, in the next-generation broadband access networks. Providing an efficient dynamic bandwidth allocation (DBA) algorithm is the most important issue for supporting multiple service classes of traffic simultaneously. This paper presents a new DBA algorithm, which is the modified version of the hybrid slot-size/rate (HSSR) scheme, and is called the modified HSSR (MHSSR) algorithm. We have also modified the control message scheduling algorithm to fit it to the proposed scheme. In the proposed MHSSR scheme, each cycle time, i.e., the length of a time cycle, is equally divided into two parts. In the 1st part of the cycle time, the bandwidth is dynamically allocated to the HP traffic of all the optical network units (ONUs). In contrast, in the 2nd part of the cycle time, the bandwidth is dynamically allocated to the BE traffic of one or multiple ONUs. Furthermore, to ensure guaranteed service for the HP traffic, the 1st part of the cycle time is extended while the 2nd part of the cycle time is compressed if the demand of the HP traffic is very high. However, the 1st part of the cycle time will never be compressed, even at the lightly loaded condition of the HP traffic. The modified control message-scheduling algorithm effectively coordinates the timing sequence between the two parts of the cycle time and ensures the synchronization between two Gate messages to each ONU. We have evaluated the performance of the proposed schemes through numerical simulations in terms of end-to-end packet delay, bandwidth wastage, remaining bytes per time cycle, jitter, and throughput for different offered loads. From the comparative analysis, it can be seen that the proposed scheme provides better performance than the existing HSSR and delay variation-guaranteed schemes.

Improving quality of service in four-channel WDM ethernet passive optical network

Energy-efficiency and green communications have become dominant topics related to access network implementation, since their energy consumption is a major contributor of energy consumption within the Internet. In this paper we analyze an implementation of a new energy-efficient dynamic bandwidth algorithm in a four-channel Wavelength Division Multiplexing Ethernet Passive Optical Network (WDM EPON), in which wavelength assignments take place per service class and not per Optical Network Unit (ONU). The improved Dynamic Bandwidth Allocation (DBA) algorithm introduces independent bandwidth allocation for each wavelength, which results in efficient bandwidth management and utilization. The mathematical model for new DBA algorithm is described, as are changes to the Multi-Point Control Protocol (MPCP), necessary for its implementation. The obtained results show that the redefined DBA algorithm improves Key Performance Indicators (KPIs) and as a consequently enables delivery of enhanced services to end-users. Significant energy savings are achieved without Quality of Service (QoS) degradation, and without network or equipment architecture changes.

A new DBA algorithm for reducing delay and solving the over-granting problem of long reach PON

The main problem of the deployment of long reach passive optical network (LR-PON) is that it suffers from larger propagation delay. Multi-thread polling (MTP) based dynamic bandwidth allocation (DBA) algorithm is one of the solutions to mitigate the larger propagation delay in the LR-PON system. However, in the conventional online MTP based DBA scheme, over-granting problem is severe. In this paper, we propose a new online MTP based DBA algorithm namely slotted MTP (S-MTP) scheme, where each time cycle is divided into multiple grant scheduling slots and, in each slot, multiple request and grant messages are processed simultaneously including the use of frame by frame information in both the request and grant messages. The proposed S-MTP scheme effectively reduces the end-to-end packet delay and over-granting problem in the LR-PON system with lower computational complexity. We have evaluated the performances of the proposed scheme by numerical simulations. The simulation results show that the proposed scheme provides 45% and 20% lower end-to-end packet delay with 38% and 10% lower over-granting rate than the conventional online MTP and enhanced interleaved polling with adaptive cycle time schemes, respectively. The S-MTP scheme also provides higher throughput and bandwidth utilization than those of the existing schemes.

Dynamic bandwidth allocation algorithm based on MUMS two-dimensional priority queue for NG-EPON with multi-transceiver ONUs

Abstract Recently, the IEEE 802.3 Ethernet Working Group has been working to explore new solutions for the next-generation Ethernet passive optical network (NG-EPON). It’s desirable for NG-EPON to support the coexistence of multi-type users and multi-type services (MUMS) on a single access platform. Moreover, in the future, ONU may be equipped with multiple transceivers to break through bandwidth limit of a single wavelength and then achieve greater throughput per ONU. In this paper, a two-dimensional priority queue model is designed for buffer differentiation management. Then, a dynamic bandwidth allocation (DBA) algorithm including joint grant sizing and scheduling is presented to carry out differentiated bandwidth allocation among MUMS. By providing different aggregated data rates and setting scalable wavelength resource pools for different users and services, flexible ONU configurations are allowed. By using time-order filling (ToF) and wavelength-order filling (WoF) in combination to realize grant scheduling, the flexibility of multi-transceiver ONUs gets further exploited. Finally, the simulation demonstrates the effectiveness of the proposed algorithm. Not only each type of service/user can get reasonable network access capacity that matches its bandwidth requirements, but the overall network performance also gets improved compared with other DBAs for NG-EPON.

A Heavy Load Optimized Dynamic Bandwidth Allocation Algorithm for Hybrid WDM/TDM VPONs

Abstract Hybrid wavelength division multiplexed (WDM)/Time division multiplexed (TDM) virtual passive optical networks (VPONs) are considered to provide cost efficient solutions for ever increasing bandwidth requirements of next generation optical access networks. With the development in technology effective bandwidth assignment has emerged as a major concern area. In this paper a novel heavy load optimized dynamic bandwidth allocation algorithm (HLO-DBA) is proposed for the hybrid WDM/TDM VPONs. Multi point control protocol of Ethernet passive optical network (EPON) is implemented for WDM/TDM VPONs subscribers. The excess bandwidth of lightly loaded subscribers is distributed among heavily loaded users through an efficient mechanism. The proposed technique effectively utilize the idle period between the last transmitted REPORT messages from previous transmission cycle (t-1) to the first GRANT message in the current cycle (t). Optical network units (ONUs) connecting the subscribers are scheduled in such a way so as to reduce the wastage of bandwidth. Performance evaluation of HLO-DBA in terms of quality of service (QOS) metrics like throughput and average delay is done to validate the optimization of the proposed mechanism.

On the efficiency and fairness of dynamic wavelength and bandwidth allocation algorithms for scheduling multi-type ONUs in NG-EPON

Abstract In the Next Generation Ethernet Passive Optical Network (NG-EPON), Optical Network Units (ONUs) can work on multiple wavelengths simultaneously to achieve higher peak rates. There are three types of ONUs (25G, 50G and 100G ONUs) sharing all the 100 Gb/s bandwidth. Each type of ONUs has a total bandwidth constraint due to ONUs’ working wavelength capabilities. In this paper, we investigate the fairness and efficiency of dynamic wavelength and bandwidth allocation (DWBA) algorithms for scheduling multi-type ONUs while considering their bandwidth capacity constraints. Proposed DWBA algorithms can achieve high efficiency, excellent fairness as well as good wavelength load balancing.

A Visualization Based Analysis on Dynamic Bandwidth Allocation Algorithms for Optical Networks

This paper presents the bibliometric analysis of Dynamic Bandwidth Allocation (DBA) algorithms in the telecommunication field using CiteSpace and Web of Science (WoS) analysis for the period of decade (2009-2018). The publication count and citation counts in the last five years have significantly increased reflecting this as active research. The visualization results identified the most influential DBA algorithms centered on 1) EPON technology addressing DBAs meeting QoS requirement (68 counts), 2) DBAs for Elastic Optical Networks (58 counts) and (3 DBAs for long reach PON (54 counts). Assi CM and Kramer G are the leading contributors and Plos One and Journal of optical communication and networking are proffered Journals. The correlation between the research contribution and expenditures countries do is 0.945. Wherein, China in countries and Beijing university of Posts and Telecommunications among research institutes contribute the most in the DBA PON research across the world.